By 2372, he had been promoted to commander and was assigned as chief science officer of the USS Slayton. The vessel was sent to Chiaros IV to calm hostilies between the government and rebel factions, and to oversee a vote on whether the planet would join the Federation or the Romulan Star Empire. Zweller's mission for Section 31 was to influence the vote in favor of the Romulans, in return for a list of Tal Shiar agents operating in the Federation. During the mission, the Slayton was destroyed and Zweller was exposed. He was taken into custody on board the USS Enterprise by his old friends Picard and Batanides, but before he could have been turned over to a starbase for a court martial he was released on the orders of AdmiralConnaught Rossa who most likely got her orders from Section 31. (TNG - Section 31novel: Rogue)